提高水管理装置橡胶隔膜寿命的理论分析

依据水管理装置工作原理，对装置在各种工作过程中隔膜的受力进行分析。分析研究表明，理论上保证隔膜长期安全运行的条件是低压驱动水泵所泵送的流体体积与高压驱动水泵所泵送的流体体积均小于隔膜变形引起的隔离器上下腔体的体积变化量以及转换阀换向严格同步。     

隔膜式蓄能器疲劳试验研究

隔膜式蓄能器是液压系统中的重要辅件,其橡胶隔膜的气密性和疲劳寿命直接影响着使用性能。文章通过模拟蓄能器真实工况条件,对隔膜式蓄能器进行了疲劳试验,分析比较了不同材质和结构型式橡胶隔膜的气密性和疲劳寿命,为液压系统中蓄能器隔膜的选材和结构设计提供了技术支撑。     

基于应力均匀化的超纯水隔膜阀隔膜优化

超纯水隔膜阀具有结构简单、耐化学腐蚀、低离子析出等优点,多用于半导体行业,隔膜的疲劳破损是影响隔膜阀寿命和设备可靠性的关键性能指标。通过COMSOL模拟了隔膜启闭过程中的应力变化情况,并详细分析了隔膜工作时的受力特点。结果表明:隔膜启闭过程中受到的应力与阀口开度成线性关系,且阀口开度最大时出现峰值;对于小流量、低流速的超纯水隔膜阀,隔膜失效的主要因素是隔膜启闭过程中机械拉伸引起的疲劳损坏;优化后的隔膜在工作时的应力趋于均匀化,对进一步提高其工作寿命具有良好的工程指导意义。     

直接氢气质子交换膜燃料电池发动机管理系统研究现状与进展

直接氢气质子交换膜燃料电池发动机是一个复杂的综合系统,各个子系统之间存在强烈的耦合。从水管理机理模型、电堆经验模型、电堆和空气系统优化和包括系统级水热管理系统的发动机综合系统优化与控制等层次上论述了发动机管理系统的重要性、研究现状和进展,并提出了将电池水热管理模型、系统优化和智能控制相结合的开发思路。     

隔膜压缩机金属隔膜故障原因分析及对策

金属隔膜是隔膜压缩机的关键元件,隔膜的使用寿命关系到压缩机的长周期运行时间.以聚丙烯中试环管装置丙烯回收压缩机为例,从压缩机工况、压缩机液压油系统以及金属隔膜材料等方面寻找隔膜压缩机隔膜故障的原因,并从油温控制、工况优化和隔膜片优化方面探索延长隔膜压缩机膜片寿命的方法.     

高浓度固液两相隔膜式输送泵的研制

该文着重介绍了高浓度固液两相隔膜式输送泵的隔膜及其隔膜控制技术,以及泵的主要技术参数、隔膜的性能特点、工作原理及结构设计.隔膜泵与一般往复泵的根本区别就在于设有隔膜,其核心就是隔膜控制技术,隔膜具有较长的使用寿命.     

消息报道

低压煤浆隔膜泵取得成果消息报道由机械部合肥通用机械研究所自主开发的“液压隔膜系用隔膜最大挠曲机械式自控机构”是一个完善的系统，它可以在动态状况下保证隔膜挠曲变形永不超出设计限定值并始终保证隔膜两侧压力平衡，使隔膜两侧压差甚小，而且操作简便。试验证明，在720小时内，反复停车、运行，不需任何调整，保证了隔膜的长寿命。由于隔膜两侧压力始终保持平衡状态，故隔膜泵可以不受排出压力高、低的限制，可以在更高的压力下正常使用。为了进一步提高隔膜的使用寿命，该系采用了特殊的预变形隔膜，目的是使隔膜挠曲变形时，内应…     

新型波纹管隔膜泵及其隔膜应力计算

提出了一种采用波纹管隔膜取代平板隔膜的新型隔膜泵;以某煤制油中试基地试验样机的波纹管隔膜为例,建立了波纹管隔膜计算模型,应用COSMOS/Works有限元软件计算了波纹管隔膜工作应力并分析了其应力分布规律.     

浅析锂电池隔膜双向拉伸线配方喂料方式

锂电池隔膜的生产原料是由聚丙烯(PP)基料和极少量的多种β成核剂、扩散剂等添加剂混合而成,添加剂直接影响着锂电池隔膜微孔的形成,母料与添加剂的均匀混合决定了隔膜微孔数量分布和孔径大小的均匀一致性,从如何能使添加剂均匀分布在原料PP中,从而生产出高品质隔膜出发,对隔膜生产线的喂料系统进行了研究和改进。     

高精度隔膜计量泵的研制

本文阐述石油化工装置中特定工况下应用的隔膜计量泵。对造成传统隔膜计量泵精度低的原因进行了分析研究,介绍计量泵变频控制系统、独创设计的安全补偿阀技术、复合隔膜和双隔膜结构、平板密封阀组设计分析以及采用加大活塞直径等来提高隔膜计量泵的精度,并对改造后的隔膜计量泵进行了试验研究,结果表明,改良型计量泵的结构设计和新型材料的选用大大提高了计量泵的精度。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....